Sieve bends are used to separate solids from a carrier medium in a slurry flowing over a screening surface of the sieve bend. The sieve bend is often arcuate and is arranged at an incline with screening apertures, or slots, perpendicular to a direction of flow of the slurry over the screening surface of the sieve bend. As the slurry flows over the inclined screening surface, solids are retained on, and pass along, the screening surface while liquid and other entrained particles of the carrier medium as well as undersized particles pass through the screening slots of the sieve bend. The separated solids retained on the screening surface are fed downstream for further processing and/or collection while the separated carrier medium is able to be recycled for re-use.
The carrier medium used in mineral processing applications is generally in the form of magnetite media which is introduced into the mineral handling and preparation circuit to provide appropriate density to volumetric flow. This provides an ability to separate size-specific particles by density due to cyclonic action generated within an upstream separation asset. The cost of this magnetite media is high and recovery of the carrier medium plays a critical part in classifying ores.
It will be appreciated that inefficient media recovery results in significant losses for a mining operation. Recovery of the carrier medium is directly related to the open area of the sieve bend. The greater the open area, the better the efficiency of the sieve bend. However, it is desirable to increase open area without increasing slot size. An increased slot size is undesirable as it would result in larger particles passing through the screening slots resulting in an excessive proportion of recoverable solids being lost.
Another major consideration in mining operations is the cost of the sieve bends themselves. It will be appreciated that the slurry is very abrasive and the slurry impacting on the screening surface of the sieve bend adversely affects the operating life of the sieve bend. Extending the wear life of the sieve bend without adversely impacting screening efficiency could result in significant cost savings for the mining operation.
Any discussion of documents, acts, materials, devices, articles, or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.